function s1_hello(){
echo "hello, world!"
}
function s2_tell_who_i_am(){
echo "$(whoami)"
}
function s3_which_distro_do_i_use(){
cat /etc/os-release|head -n 1 |grep "NAME"
}
function s4_view_my_cpu_arch(){
uname -m
}
function s5_show_first_scsi_disk_size(){
lsblk -l | \grep disk | \grep '^sda ' |awk '{print $4}'
}
function s6_show_main_memory_size_in_megabytes(){
free -m | grep "Mem:" |awk '{printf $2}'
}
